The storage of information or data has seen revolutionary changes in the past century, yet the long term storage and interpretation of such data may present an important problem. Rothenberg, Scientific American, pp. 42-47, 1995, describes the problems associated with the longevity of documents.
The storage of information or data storage has commonly involved the use of magnetic or optical recording carriers. Recently, the use of scanning tunnel microscopes (STM's) has been investigated for the writing and reading of storage information by means of topographical changes to flat metal surfaces. Wiesendanger, J. Vac. Sci. Technol. B, v. 12, no. 2, pp. 515-529 (1994), reviews STM and similar scanning probe microscopy in fabrication of nanometer-scale structures and the unresolved problems of the limited temporal stability of such nanometer-scale structures. Other similar references include: Adamchuk et al., Ultramicroscopy v. 45, pp. 1-4 (1992), describing the use of an STM to microprocess nanometer-sized craters of about 50 nanometers (nm) in diameter and 10 nm in depth in gold films on flat silicon substrates; Li et al., Appl. Phys. Lett., v. 54, no. 15, pp. 1424-1426 (1989), describing electroetching nanometer-sized craters about 2 nm in diameter and up to about 1 nm in depth in flat gold substrates with a STM operating in air; Silver et al., Appl. Phys. Lett., v. 51, no. 4, pp. 247-249 (1987), describing the direct writing of submicron metallic features by deposition of a new substance (cadmium from organometallic gas) on a surface with a STM; and, Abraham et al., IBM J. Res. Develop v. 30, no. 5, pp. 492-499 (1986), describing surface modification with a STM via surface diffusion and mention the possibility of high density memory storage. The present data storage systems each suffer from one or more problems including the long term stability or durability of the medium.
U.S. patent application Ser. No. 08/382,345, now U.S. Pat. No. 5,721,687 entitled "Ultrahigh Vacuum Focused Ion Beam Micromill and Articles Therefrom", by Lamartine et al. describes the use of a focused ion beam in combination with an ultrahigh vacuum to obtain milled articles having a high aspect ratio. While this process could prepare suitable durable data storage media, the process was slow.
It is an object of this invention to provide a rapid process of forming durable data storage media such a process involving the use of an etch enhancement or an etch stop technique.
It is another object of this invention to provide articles of manufacture formed by the present process, such articles including, e.g., durable data storage media, such articles of manufacture containing detectable residual amounts of ions initially used in the preparation process.